TB 8 - Electrical Hazards

Question 1

How many deaths per year?

Answer 1

700

Question 2

What are AMPs?

Answer 2

Current flow (GPM)
* It’s what flows on a wire or conductor

Question 3

What are Volts?

Answer 3

Electrical pressure or push measured in volts

Question 4

OHMS

Answer 4

Watts = Amps x Volts
Amps = Watts / Volts
Volts = Watts / Amps

Question 5

What is OHMS Law?

Answer 5

One OHM is the resistance value through which one volt will maintain a current of one AMPERE.

Question 6

WATTs?

Answer 6

Power is the amount of current times the voltage level at a given point measured in wattage or watts

Question 7

Extremely high voltage?

Answer 7

60,000 +

Question 8

High voltage?

Answer 8

600 - 59,999 volts

• usually found in customer distribution system = primaries (typically 4,800 kv)

Question 9

What’s considered Low voltage?

Answer 9

600 volts

Question 10

Electricity to Fire Hydraulics?
Conductor =
Current=
Voltage=
Amperes =
OHMS =

Answer 10

Hose
Water
Pressure
GPM
FL

Question 11

Generation facilities generate how many volts?

Answer 11

4,000 - 20,000 volts

Question 12

What do switching stations do?

Answer 12

Considered a step up transformer and sends long distances sometimes over 1 million volts

Question 13

The transmission system consist of two components?

Answer 13

Grid - layout of electrical distribution system
Transmission lines - carry electricity from gen stations

Question 14

Transmission lines voltage ranges?

Answer 14

69kv - 1000kv
* Most of the transmission lines coming into LA are 230 kv

Question 15

Insulators spacing range from __ft?

Answer 15

3 - 20 ft long

Question 16

Underground transmission lines in most congested areas if the city range from ____kv?

Answer 16

138kv - 230 kv

Question 17

LADWP has how many receiving stations?

Answer 17

21

Question 18

RECEIVING STATION BREAK DOWN -

Answer 18

Receive voltages of 138kv to 500kv and step it down to 34.5kv ; which is known as sub-transmission.

There are 150 distributions stations that receive volts of 34.5 kv and step it down to 4.8 kv ( known as primary circuit)

Question 19

Each primary serves approx. how many customers?

Answer 19

750

Question 20

What are high voltage capacitors?

Answer 20

-Stores energy
- Hold deadly charge
- Older versions contain chemicals

Question 21

Overhead transformers step down voltage from 4.8kv to ____v

Answer 21

120/240

Question 22

4 types of electrical shock?

Answer 22

1) Electrocution
2) Electrical Shock
3) Burns
4) Falls

Question 23

___th of an amp going through the body for __ sec can cause death

Answer 23

1/10th

2 seconds

Question 24

Currents above ___mA can paralyze or muscles to freeze

Answer 24

10mA

Question 25

Muscle tissue burns at __mA?

Answer 25

5

Question 26

People have stopped breathing from volts as low as __ volts.

Answer 26

49

Question 27

How many ____mA of current does it take to causes respiratory paralysis?

Answer 27

30 mA

Question 28

Overhead communication lines can be energized with up to ___ v

Answer 28

50

Question 29

Rescue considerations for electrical emergencies Pt trapped in cars should remain in car and attempt to drive clear of wires of how many feet minimum? Remain how many feet from outermost wire of transmission line?

Answer 29

35 ft min 100ft

Question 30

Spotting apparatus Spot app at least __ span ( the distance of __ poles) from affected wire or pole?

Answer 30

One Two

Question 31

Electrical Hazards - WILD LAND Safe distance from transmission lines/ towers? What’s the clearance?

Answer 31

35 ft A minimum of 100 ft beyond the outermost wire

Question 32

Vault/manhole fire Main fire hazards lies in the cooling oil which has a flash point of ___f

Answer 32

300°f

Question 33

Carbon monoxide explosive range

Answer 33

12.5 - 74

Question 34

Manhole covers weigh ____lbs and can be thrown ___ft into the air and up to ___ft away.

Answer 34

300 lbs 75ft 125ft

Question 35

High voltage cables up to ______volts may be located close to the floor inside a conduit. Cooling oil in underground vaults is pressurized to __psi oil pressure

Answer 35

230,000 volts 200 psi oil pressure

Question 36

According to TB 008 Electrical Hazards at Fires, extremely high voltage is in excess of ______ volts.

Answer 36

60,000 volts

Question 37

According to TB 008 Electrical Hazards at Fires, what is the main fire hazard in an electrical vault?

Answer 37

Cooling oil used in transformers

Question 38

According to TB 008 Electrical Hazards at Fires, how far and how high have manhole covers been blown away?

Answer 38

75 feet high; 125 feet away

Question 39

According to TB 008 Electrical Hazards at Fires, how often does LADWP test the rubber gauntlet gloves and at how many volts?

Answer 39

10,000 volts and every 60 days

Question 40

According to TB 008 Electrical Hazards at Fires, high voltage is from _____ to _____ volts.

Answer 40

600 to 59,999

Question 41

According to TB 008 Electrical Hazards at Fires, the overhead communication cables normally found on the lowest level of a power pole can be energized with up to how many volts?

Answer 41

50 Volts

Question 42

According to TB 008 Electrical Hazards at Fires, the primary distribution lines are usually ________ in the LADWP system.

Answer 42

4.8kv

Question 43

According to TB 008 Electrical Hazards at Fires, LADWP has how many receiving stations?

Answer 43

21

Question 44

According to TB 008 Electrical Hazards at Fires, high-voltage capacitors have been known to retain a deadly electrical charge for _________ after power has been removed from the circuit?

Answer 44

weeks

Question 45

According to TB 008 Electrical Hazards at Fires, the severity of injury from electrical shock depends on the amount of electrical current and the length of time the current passes through the body. An amperage of ______ going through the body is enough to cause death?

Answer 45

1/10 amp

Question 46

According to TB 008 Electrical Hazards at Fires, when can department members work in violation of the Aerial proximity to power lines policy and what shall the Apparatus Operator do to provide for personnel safety?

Answer 46

Participating in an actual rescue attempt; AO shall remain at the pedestal